AQP4 and Alzheimer disease: However, the present study showed a significant increase in the expression of AQP4 in the brains of APP/PS1 mice, which is in accordance with some human and animal studies (Hoshi et al., 2012; Xu et al., 2015).The above inconsistent results in AQP4 expression in AD may be associated with the different stages of disease, specific neuroanatomical areas, and whether patients had complications or not.